GB/T 898-1988
Double end studs b1=1.25d-type A
GB/T 898-1988
Double end studs b1=1.25d-type B
GB/T 13807.2-1-2008
Type S Double end studs(d≥64mm)-Table 1
GB/T 13807.2-1-1992
Type S Double end studs(d≥64mm)-Table 1